Summary: Behavioral/Systems/Cognitive
Deep Brain Stimulation of the Subthalamic Nucleus Alters
the Cortical Profile of Response Inhibition in the Beta
Frequency Band: A Scalp EEG Study in Parkinson's Disease
Nicole Swann,1,2 Howard Poizner,2,3 Melissa Houser,4 Sherrie Gould,4 Ian Greenhouse,1 Weidong Cai,1 Jon Strunk,1
Jobi George,1 and Adam R. Aron1,2
1Department of Psychology, 2Neuroscience Graduate Program, and 3Institute for Neural Computation, University of California San Diego, La Jolla,
California 92093, and 4Scripps Green Hospital, La Jolla, California 92037
Stopping an initiated response could be implemented by a fronto-basal-ganglia circuit, including the right inferior frontal cortex (rIFC)
andthesubthalamicnucleus(STN).Intracranialrecordingstudiesinhumansrevealanincreaseinbeta-bandpower( 16­20Hz)within
the rIFC and STN when a response is stopped. This suggests that the beta-band could be important for communication in this network. If
this is the case, then altering one region should affect the electrophysiological response at the other. We addressed this hypothesis by
recording scalp EEG during a stop task while modulating STN activity with deep brain stimulation. We studied 15 human patients with
Parkinson's disease and 15 matched healthy control subjects. Behaviorally, patients OFF stimulation were slower than controls to stop
their response. Moreover, stopping speed was improved for ON compared to OFF stimulation. For scalp EEG, there was greater beta
power,aroundthetimeofstopping,forpatientsONcomparedtoOFFstimulation.Thiseffectwasstrongerovertherightcomparedtoleft
frontalcortex,consistentwiththeputativerightlateralizationofthestoppingnetwork.Thus,deepbrainstimulationoftheSTNimproved
behavioral stopping performance and increased the beta-band response over the right frontal cortex. These results complement other
evidence for a structurally connected functional circuit between right frontal cortex and the basal ganglia. The results also suggest that
deepbrainstimulationoftheSTNmayimprovetaskperformancebyincreasingthefidelityofinformationtransferwithinafronto-basal-